Heterostructure for electronic power components, optoelectronic or photovoltaic components

Abstract

A heterostructure that includes, successively, a support substrate of a material having an electrical resistivity of less than 10−3 ohm·cm and a thermal conductivity of greater than 100 W·m−1·K−1, a bonding layer, a first seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, a second seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and an active layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and being present in a thickness of between 3 and 100 micrometers. The materials of the support substrate, the bonding layer and the first seed layer are refractory at a temperature of greater than 750° C., the active layer and second seed layer have a difference in lattice parameter of less than 0.005 Å, the active layer is crack-free, and the heterostructure has a specific contact resistance between the bonding layer and the first seed layer that is less than or equal to 0.1 ohm·cm2.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a heterostructure for the manufacture of electronic power components or optoelectronic components, or photovoltaic components successively comprising from its base to its surface:[0002]a support substrate,[0003]a bonding layer,[0004]a crack-free monocrystalline layer, so-called “active layer”, of a material of composition AlxInyGa(1-x-y)N, where 0≦x≦1, 0≦y≦1 and x+y≦1, presenting a thickness of between 3 and 100 micrometers, in which or on which the components are manufactured.BACKGROUND OF THE INVENTION[0005]For the vertical or planar electronic power device (MOS components, bipolar transistors, J-FET, MISFET, Schottky or PIN diodes, thyristors), optoelectronic component (Laser, LED) and photovoltaic component (solar cells) market, it is interesting to utilize an AlxInyGa(1-x-y)N (x between or equal to 0 and 1, y between or equal to 0 and 1, x+y less than or equal to 1) conducting substrate and preferably a bulk GaN (or “...

AI Technical Summary

Benefits of technology

The proposed heterostructure achieves a thick, crack-free AlxInyGa(1-x-y)N layer with improved electrical and thermal conductivity, reduced dislocation density, and simplified manufacturing, addressing the limitations of existing technologies by providing a stable and efficient growth method for electronic, optoelectronic, and photovoltaic components.

Problems solved by technology

These substrates are, however, difficult to manufacture with current technologies and remain very expensive.

But the growth of thick layers with a good crystalline quality is still difficult with current methods if the seed substrate is not of the same material as the material epitaxied.

The epitaxy of a thick layer of GaN (approximately 10 micrometers) on a seed substrate such as doped Si or SiC, due to the differences in the coefficient of thermal expansion (CTE) and lattice parameter between the materials, leads to the formation of defects and cracks in the layer which reduces the effectiveness of the electronic, optical or optoelectronic devices formed on this material.

The epitaxy of a thick layer of GaN on a sapphire substrate followed by the transfer of the layer to a conductive substrate by laser detachment is an expensive process.

In addition, the choice of these materials does not allow a dislocation density of less than 107 cm−2 to be reached in the active layer.

In addition, the layer thus formed presents very significant bending which necessitates long preparation steps (polishing, etc.) so that it may be bonded and transferred to a final substrate.

In addition, the transfer of a layer of GaN from a bulk substrate by the Smart Cut™ technology does not enable the desired thicknesses to be reached in a satisfactory manner to date.

This method is complex since it involves two transfers of the active layer of GaN to form the final conductive structure.

This method is thus complex since it involves the use of two different support substrates, the first one for the epitaxial growth of the active layer, the second one for the operation of the component.

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